Companion Planting

Did you know plants have best friends and enemies?  Your garden beds might as well be a catty high school cafeteria and you don’t want the potatoes sitting down at the tomato’s table.  Ok, maybe it’s not quite that bad (maybe I just have too many teenagers running around my house!).  Plants do have “friends” and just like human friendships, plant friends help each other grow.  This is called companion planting.

The science behind Companion Planting

There are plenty of ways plants can help each other out.  Tall plants (like sunflowers) can help shade short shade-loving plants (like lettuce).  Sometimes a companion can deter pests that like to go after their friend.  Nematodes love to eat melons but they hate the smell of marigolds. By planting them together you can naturally deter nematodes.

Bean vines attract beneficial insects (like spiders) that like to prey on insects that will eat your corn.  Onion’s strong smell can deter many kinds of pests.  Sometimes companions can enhance the taste of plants they are sharing soil with.  Basil will improve most plants but works especially well with tomatoes.  Dill & cucumbers are another obvious pairing.

Companion plants can be plants that complement rather than compete for resources.  Beans help fix soil by adding in extra nitrogen, something that nitrogen-loving tomatoes would appreciate. Calendula attracts a wide range of pollinators. This makes it a great friend for lots of plants that flower, like squash and cucumbers.

The entire concept of companion planting just reinforces my belief that your garden is meant to be a diverse mix, not rows and rows of the same plant!  A great way to showcase companion planting is in a square foot garden – click here to learn about square foot gardening

Bad Pairings

With every good there comes some bad.  There are some plant pairings that you should avoid.  Nightshade family members like potatoes and tomatoes are affected by the same types of blight.  Planting them together can contribute to the spread of disease.  They also are both heavy nitrogen feeders so they could compete for resources, stunting the growth of both.  A tomato’s extensive root system can stunt the growth of carrots.  Onions & beans can also stunt each other’s growth.

Ready to try companion planting?

Below you will find a guide to some of the most commonly found plants for gardeners.  “Friends” are plants that will help that plant, and “enemies” will hinder that plant.  They aren’t always the same!  A good example is with carrots & tomatoes.  Carrots planted near tomatoes could be stunted by the huge root structure of the tomato, however, the tomato will grow better & be more flavorful.  This makes carrots a friend of tomatoes, but tomatoes are an enemy of carrots.  Planting flowers like marigolds, calendula, sunflowers & nasturtiums can make your garden gorgeous and more diverse. The flowers will also attract a ton of pollinators and beneficial insects so it’s a great idea to sprinkle them all around!

Companion Planting Guide

• Asparagus
  friends: tomatoes, parsley
  enemies: onions, garlic, potatoes
• Basil
  friends: tomatoes, asparagus & peppers – but pretty much everyone!
  enemies: none
• Beans, Bush
  friends: beets, cabbage, carrots, cauliflower, corn, cucumbers, marigolds, potatoes, strawberries
  enemies: garlic, leeks, onions, shallots

• Beans, Pole
  friends: corn, marigolds, potatoes, radishes
  enemies: beets, garlic, leeks, onions, shallots
• Brassicas (broccoli, Brussels sprouts, cabbage, cauliflower..)
  friends:  beets, chamomile, dill, mint, rosemary, sage, onions, garlic
  enemies: tomatoes, potatoes, eggplant, strawberries
• Carrot
  friends: lettuce, onions, peas, radishes, rosemary
  enemies: dill, parsnips, tomatoes, potatoes
• Corn
  friends: beans, cucumbers, melons, peas, pumpkins, squash, sunflowers
  enemies: tomatoes, celery
• Cucumber
  friends: beans, cabbage, corn, radishes, sunflowers, marigolds, carrots, dill
  enemies: late potatoes
• Eggplant
  friends: green beans, peppers, potatoes, tomatoes, peas, spinach
  enemies: none
• Garlic
  friends: cabbage, cane fruits, roses, tomato, celery, lettuce, potatoes, tomatoes
  enemies: peas, beans
• Lettuce
  friends: beets, carrots, parsnips, radishes, strawberries, onions, cucumbers, sunflowers
  enemies: cabbage, celery, parsley
• Marigold (Calendula)
  friends: everyone!
  enemies: none
• Melons
  friends: corn, marigolds, nasturtiums, pumpkin, radish, squash, sunflowers
  enemies: potatoes
• Nasturtiums
  friends: apples, beans, cabbage, potatoes, pumpkins, radishes, squash, cucumbers, tomatoes
  enemies: none
• Onion
  friends: beets, cabbage, carrots, lettuce, parsnips, dill, strawberries, tomatoes
  enemies: beans, peas, asparagus
• Oregano
  friends: everyone!
  enemies: none
• Peas
  friends: beans, carrots, corn, cucumbers, early potatoes, radishes, turnip, mint, strawberries, eggplant
  enemies: garlic leeks, onions, shallots
• Peppers
  friends: basil, carrots, eggplant, onions, parsley, tomatoes, sunflowers
  enemies: beans, kale, Brussels sprouts
• Potato
  friends: basil, beans, cabbage, corn, eggplant, marigolds, peas, squash, garlic
  enemies: carrots, sunflowers, cucumber, pumpkin, tomato, melons
• Spinach
  friends: celery, cauliflower, eggplant, strawberries, peas, beans
  enemies: potato
• Strawberries
  friends: bush beans, lettuce, spinach, garlic, onions, peas
  enemies: brassicas
• Sunflowers
  friends: cucumbers, squash, pumpkins
  enemies: potatoes
• Tomatoes
  friends: asparagus, basil, cabbage, carrots, parsley, onions, rosemary, sage, marigold, corn, beans
  enemies: fennel, potatoes, dill, walnut trees